The subject matter described herein relates generally to the field of electronics and more particularly to power management for wireless devices.
Power management schemes are used in conjunction with wireless devices, e.g., to extend the battery lifetime of mobile networking devices. It is becoming increasingly common to find broadband wireless networking capabilities in mobile platform using technologies like IEEE 802.11, 802.16e, etc. In such wireless networks a wireless base station connects at least one wireless device to the network infrastructure. Wireless adaptors in mobile devices have multiple power states, e.g., transmit, receive, idle, sleep and off. In the idle mode, there is no transmit or receive but the transceiver is still on. When there is no data to transmit or receive, the wireless adaptor goes into sleep mode while being still connected to the network. In the sleep mode, the transceiver is turned off for fixed amounts of time that has been pre-negotiated with the base station or access point. During this time, data directed to the mobile device is buffered by the base station. After the sleep duration expires, the transceiver is turned on to check if the base station has buffered any data for the device. The mobile device exits sleep mode if there is buffered data, or if at any time data is to be transmitted to the base station.
In current mobile platforms, there is no notification from the wireless adaptor to the CPU host platform indicating when the adaptor is going into sleep states. This limits the availability of additional power management mechanisms on the host mobile platform.